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Author Topic: When to run "Reduce Overlap", and what to follow it with?  (Read 1275 times)

CheeseAndJamSandwich

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When to run "Reduce Overlap", and what to follow it with?
« on: July 03, 2021, 12:28:05 PM »
I have a big project with many thousands of images, but the scanning unavoidably has too much overlap.   If i run 'Reduce Overlap' set to 8, it halves the number of cameras and gives much better processing times, and great quality results!!!  :D 8)

But what is the correct time to run it in the workflow???
Before, after running 'Gradual Selection' tasks???
And do i need to do anything after it?
Optimise Cameras?

Do i also need to delete the disabled cameras?  Are their tie-points removed?  EDIT: They're not disabled with the cameras, so only deleting them actually gets rid of extra tie-points.
And how would i delete them if i only have Standard, and can't run scripts?

Cheers.
« Last Edit: July 20, 2021, 02:05:41 AM by CheeseAndJamSandwich »

CheeseAndJamSandwich

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Re: When to run "Reduce Overlap", and what to follow it with?
« Reply #1 on: August 28, 2021, 07:27:18 AM »
OK, So we can now sort by 'Enabled' in the Details tab of the Photos pane, and then delete all the disabled cameras.  Sweet.
That deletes them from the project along with their points, etc.

I'm still looking for more info or people with experience of using Reduce Overlap.
When in the workflow should we use it?
What values to set it to?  And scenarios to set it higher/lower.

Cheers.

cbnewham

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Re: When to run "Reduce Overlap", and what to follow it with?
« Reply #2 on: August 28, 2021, 02:23:04 PM »
I can't say I've found it useful for sculpture. I have huge amounts of overlap in order to make sure I have no holes or badly meshed parts of the model. If I use "reduce overlap" on any setting the results are nearly always worse. I've decided it is not worth my time experimenting with this feature and just put up with extended processing times using all the photos to get a result I know will be accurate.

Perhaps it works better on UAV work?


CheeseAndJamSandwich

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Re: When to run "Reduce Overlap", and what to follow it with?
« Reply #3 on: September 08, 2021, 09:46:49 AM »
I've been using an overlap of 8
I tried 6, but i landed up with a few holes in trickier, shadowed areas of the UW scans.

I've also been running Optimise Cameras afterwards... Is this needed?

SimonBrown

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Re: When to run "Reduce Overlap", and what to follow it with?
« Reply #4 on: September 08, 2021, 10:39:37 AM »
I've also been running Optimise Cameras afterwards... Is this needed?

Yes...but the primary advantages of accuracy and the outputs used to measure the changes recursive optimisation brings can only be fully realised and exploited in the Professional version.

For representative shape models the Std version creates I think it's of limited value - unless anyone knows differently?
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cbnewham

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Re: When to run "Reduce Overlap", and what to follow it with?
« Reply #5 on: September 08, 2021, 07:22:38 PM »
I've also been running Optimise Cameras afterwards... Is this needed?

Yes...but the primary advantages of accuracy and the outputs used to measure the changes recursive optimisation brings can only be fully realised and exploited in the Professional version.

For representative shape models the Std version creates I think it's of limited value - unless anyone knows differently?


I've used the optimisation (standard edition) and it appears to make little to no difference. So perhaps there is an element of truth to this.